public int compareTo(Object other) {
      int thisLoc = mStart.getLocation();
      int thatLoc = ((Entry) other).mStart.getLocation();

      if (thisLoc < thatLoc) {
        return -1;
      } else if (thisLoc > thatLoc) {
        return 1;
      } else {
        return 0;
      }
    }
 public String toString() {
   return "start_pc=" + mStart.getLocation() + " => " + "line_number=" + mLineNumber;
 }
 public boolean equals(Object other) {
   if (other instanceof Entry) {
     return mStart.getLocation() == ((Entry) other).mStart.getLocation();
   }
   return false;
 }